Search Results

Search found 42585 results on 1704 pages for 'java api'.

Page 271/1704 | < Previous Page | 267 268 269 270 271 272 273 274 275 276 277 278  | Next Page >

  • groovy call private method in Java super class

    - by Jeff Storey
    I have an abstract Java class MyAbstractClass with a private method. There is a concrete implementation MyConcreteClass. public class MyAbstractClass { private void somePrivateMethod(); } public class MyConcreteClass extends MyAbstractClass { // implementation details } In my groovy test class I have class MyAbstractClassTest { void myTestMethod() { MyAbstractClass mac = new MyConcreteClass() mac.somePrivateMethod() } } I get an error that there is no such method signature for somePrivateMethod. I know groovy can call private methods but I'm guessing the problem is that the private method is in the super class, not MyConcreteClass. Is there a way to invoke a private method in the super class like this (other than using something like PrivateAccessor)? thanks Jeff

    Read the article

  • Books recommendation to learn about java networking

    - by elec
    In order to cover for my (glaring) lack of knowledge in the basics of networking, I'm looking for a book which would ideally cover: - 1 or 2 chapters on the transport layer: tcp, udp... - 1 or 2 chapters on the application layer: http, dns... - rest of the book would be devoted to pratical way of sending data across the wire using Java-related technologies. This would involve discussions about existing products (eg. hessian, protobuf, thrift, tibco...) , performances comparisons, case studies...etc.. Does such a book exist ?

    Read the article

  • Java exception reading xml file

    - by xain
    Hi, I have the following xml file: <?xml version="1.0" encoding="UTF-8"?> <c1> <c2 id="0001" n="CM" urlget="/at/CsM" urle="/E/login.jsp"> </c2> <c2 id="0002" n="C2M" urlget="/a2t/CsM" urle="/E2/login.jsp"> </c2> </c1> I'm trying to load c2's attributes this way: Document d = DocumentBuilderFactory.newInstance() .newDocumentBuilder() .parse("epxy.xml"); Element c1 = d.getDocumentElement(); Element c2 = (Element)c1.getFirstChild(); while (c2 != null) { ... c2 = (Element)c2.getNextSibling(); } But I get the exception java.lang.ClassCastException: org.apache.xerces.dom.DeferredTextImpl incompatible with org.w3c.dom.Element in the line Element c2 = (Element)c1.getFirstChild(); before the loop. Any hints ? Thanks.

    Read the article

  • java/swing: Shape questions: serializing and combining

    - by Jason S
    I have two questions about java.awt.Shape. Suppose I have two Shapes, shape1 and shape2. How can I serialize them in some way so I can save the information to a file and later recreate it on another computer? (Shape is not Serializable but it does have the getPathIterator() method which seems like you could get the information out but it would be kind of a drag + I'm not sure how to reconstruct a Shape object afterwards.) How can I combine them into a new Shape so that they form a joint boundary? (e.g. if shape1 is a large square and shape2 is a small circle inside the square, I want the combined shape to be a large square with a small circular hole)

    Read the article

  • How to write a virtual conditional breakpoint in java

    - by Phuong Nguyen de ManCity fan
    I'm sorry if the question title may mis-inform you, but I cannot find a proper word to explain that. If you ever working with .NET, you would know that there is Assert class that will automatically wake up and attach debugger if necessary and then have debugger (Visual Studio) pausing at the Assert command, given the Assert command failed. Given I'm running a java program and having debugger connected, then how can I have debugger to break on certain condition without manually setup a break point? I'm expecting something like that: void doSomeThing(String x){ if (x==null) breakDebuggerNow(); }

    Read the article

  • Working with arrays of lists pattern in java

    - by Mad Wombat
    I am writing a card game in java where I need to spread cards from a deck into several columns until I have fixed amount of cards left. This is how I do this. public class Column extends ArrayList {} List deck = Cards.createNewDeck(); Column[] columns = new Column[10]; int c = 0; while (deck.size() 50) { if (c == 10) { c = 0; } if (columns[c] == null) { columns[c] = new Column(); } columns[c].add(Cards.dealTopCard(deck)); c += 1; } This somehow seems clunky. Is there a more readable/comprehensive way of doing the same thing?

    Read the article

  • augment the factory pattern in java

    - by TP
    I am trying to use a factory pattern to create a QuestionTypeFactory where the instantiated classes will be like MultipleChoice, TrueFalseQuestion etc. The factory code looks something like this class QuestionFactory { public enum QuestionType { TrueFalse, MultipleChoice, Essay } public static Question createQuestion(QuestionType quesType) { switch (quesType) { case TrueFalse: return new TrueFalseQuestion(); case MultipleChoice: return new MultipleChoiceQuestion(); case Essay: return new EssayQuestion(); } throw new IllegalArgumentException("Not recognized."); } } This works ok for now. If I want to add another question type I will need to modify the factory class and I do not want to do that. How can I set it up so that each question class registers itself with the Factory so that when I add a new question type, I do not have to change the code for the factory? I am a bit new to java and am not sure how to do this.

    Read the article

  • What to do of exceptions when implementing java.lang.Iterator

    - by Vincent Robert
    The java.lang.Iterator interface has 3 methods: hasNext, next and remove. In order to implement a read-only iterator, you have to provide an implementation for 2 of those: hasNext and next. My problem is that these methods does not declare any exceptions. So if my code inside the iteration process declares exceptions, I must enclose my iteration code inside a try/catch block. My current policy has been to rethrow the exception enclosed in a RuntimeException. But this has issues because the checked exceptions are lost and the client code no longer can catch those exceptions explicitly. How can I work around this limitation in the Iterator class? Here is a sample code for clarity: class MyIterator implements Iterator { @Override public boolean hasNext() { try { return implementation.testForNext(); } catch ( SomethingBadException e ) { throw new RuntimeException(e); } } @Override public boolean next() { try { return implementation.getNext(); } catch ( SomethingBadException e ) { throw new RuntimeException(e); } } ... }

    Read the article

  • java keytool question

    - by user384706
    Hi, I created a java keystore programmatically of type jks (i.e. default type). It is initially empty so I created a DSA certificate. keytool -genkey -alias myCert -v -keystore trivial.keystore How can I see the public and private keys? I.e. is there a command that prints the private key of my certificate? I could only find keytool -certreq which in my understanding prints the certificate as a whole: -----BEGIN NEW CERTIFICATE REQUEST----- MIICaTCCAicCAQAwZTELMAkGA1UEBhMCR1IxDzANBgNVBAgTBkdyZWVjZTEPMA0GA1UEBxMGQXRo BQADLwAwLAIUQZbY/3Qq0G26fsBbWiHMbuVd3VICFE+gwtUauYiRbHh0caAtRj3qRTwl -----END NEW CERTIFICATE REQUEST----- I assume this is the whole certificate. How can I see private (or public key) via keytool? Thank you

    Read the article

  • Java - binary compatibility of abstract class & subclasses

    - by thSoft
    In Java, I define an abstract class with both concrete and abstract methods in it, and it has to be subclassed independently by third-party developers. Just to be sure: are there any changes I could make to the abstract class that are source compatible with their classes but not binary compatible? In other words: after they have compiled their subclasses, could I change the abstract class - apart from e.g. adding an abstract method to it or removing a protected method from it that is called by subclasses, which are of course source incompatible - in a way that could force them to recompile their subclasses?

    Read the article

  • mp3 downsampling / compression in java

    - by veenit33
    Well, i was looking forward to modify the bit rate of a mp3 file in java. I want to downsample(change its bit rate) the mp3 file from 256/384 kbps to say 64/128 kbps.. (I guess this is the only way one can achieve mp3 compression..or is there any other way.?) I searched for LameOnJ but that website is temperoraly down and so im not able to get the license file which we need to download in every 2 days. Is this possible using JMF..? What are the other option i have..? Regards, Veenit Shah

    Read the article

  • Play wave file using AudioFormat in java

    - by angelina
    Dear all, I m getting following exception while running my code on linux operating system.This code works fine on windows operating system.below is the exception and code used. java.lang.IllegalArgumentException: No line matching interface Clip supporting format PCM_SIGNED unknown sample rate, 16 bit, stereo, 4 bytes/frame, big-endian is supported. AudioFormat format = sourceaudio.getFormat(); format = new AudioFormat( AudioFormat.Encoding.PCM_SIGNED, format.getSampleRate(), format.getSampleSizeInBits() * 2, format.getChannels(), format.getFrameSize() * 2, format.getFrameRate(), true); AudioFileFormat.Type targettype = AudioFileFormat.Type.WAVE; AudioInputStream targetaudiostream = AudioSystem.getAudioInputStream(format, sourceaudio); sourceaudio.close(); targetaudiostream.close(); System.out.println("55555555"); URL url = new URL("http://localhost:8084/newvideo/PCMfile.wav"); Clip clip = AudioSystem.getClip(); AudioInputStream ais = AudioSystem.getAudioInputStream(url); clip.open(ais); System.out.println("seconds: " + (clip.getMicrosecondLength() / 1000000));

    Read the article

  • Writing out BMP files with DataBuffer.TYPE_FLOAT or DataBuffer.TYPE_DOUBLE in java

    - by Basil Dsouza
    Hi Guys, I had a problem working with the image classes in java. I am creating a buffered image with DataBuffer.TYPE_DOUBLE. This all works fine in memory (I think). But the problem starts when I try to write it using ImageIO.write. Initially I was getting no exception at all and instead was only getting an empty output file for my troubles.. After a bit of poking around in the code, i found out that the bmp writer doesnt support writing type_double type of files. From: BMPImageWriterSpi.canEncodeImage: if (dataType < DataBuffer.TYPE_BYTE || dataType > DataBuffer.TYPE_INT) return false; So my question is, does anyone have a way of writing out those kind of images to disk? any documentation or tutorial, or link would be helpful. Thanks, Basil Dsouza

    Read the article

  • Assigning a default value to a final variable in case of an exception in Java

    - by frenetisch applaudierend
    Why won't Java let me assign a value to a final variable in a catch block after setting the value in the try block, even if it is not possible for the final value to be written in case of an exception. Here is an example that demonstrates the problem: public class FooBar { private final int foo; private FooBar() { try { int x = bla(); foo = x; // In case of an exception this line is never reached } catch (Exception ex) { foo = 0; // But the compiler complains // that foo might have been initialized } } private int bla() { // You can use any of the lines below, neither works // throw new RuntimeException(); return 0; } } The problem is not hard to work around, but I would like to understand why the compiler does not accept this. Thanks in advance for any inputs!

    Read the article

  • Eclipse Java Profiler

    - by Jeff Storey
    I know this has been asked before, but I have not found anything recent that really gives a good answer. I'm trying to find a free profiler for eclipse that works well. I would like a graphical breakdown of execution time in particular. I've tried TPTP but have had no luck at all with GUI apps (it took almost a minute for a GUI app to start and was virtually unusable on screen - it uses a lot of Java OpenGL, so I'm not sure if it has to do with that). I liked YourKit, but unfortunately it's not free. I even tried switching to NetBeans since they have a built in profiler. If anyone has had success with particular profilers (even if it was TPTP), I'd like to hear about it. Any recommendations would be greatly appreciated. thanks, Jeff

    Read the article

  • When using the getInstance() method of the abstract java.text.NumberFormat class, what is the actual

    - by iamchuckb
    This question expands upon the one at abstract-class-numberformat-very-confused-about-getinstance. I feel that this question is different enough to merit being asked on its own. In the answers to that question, it was stated that a code statement such as NumberFormat en = NumberFormat.getInstance(Locale.US); returns an object that is a subclass of the java.text.NumberFormat class. It makes sense to me why the return type can't be just an instance of NumberFormat since that is an abstract class. Rather, it was stated that the returned object is at least an instance of NumberFormat, but actually something else. My question is this: what specifically is the class of the object that is returned? In the Sun documentation the only subclasses I see are ChoicesFormat and DecimalFormat. Is there some sort of behind the scenes compiler voodoo going on here? Thanks in advance!

    Read the article

  • Read data from a text file using Java

    - by Saran
    I need to read a text file line by line using Java. I use available() method of FileInputStream to check and loop over the file. But while reading, the loop terminates after the line before the last one. i.e., if the file has 10lines, the loop reads only the first 9 lines. Snippet used : while(fis.available() > 0) { char c = (char)fis.read(); ..... ..... }

    Read the article

  • What causes "java.lang.IncompatibleClassChangeError: vtable stub"?

    - by JimN
    What causes "java.lang.IncompatibleClassChangeError: vtable stub"? In our application, we have seen this error pop up randomly and very seldom (just twice so far, and we run it a lot). It is not readily reproducible, even when restarting the app, using the same jvm/jars without rebuilding. As for our build process, we clean all classes/jars and rebuild them, so it's not the same problem as others have encountered where they made a change in one class and didn't recompile some other dependent classes. This is unlike some of the other questions related to IncompatibleClassChangeError -- none of them mention "vtable stub". In fact, there are surprisingly few google results when searching for "IncompatibleClassChangeError "vtable stub"".

    Read the article

  • javax script how to call a function in JavaScript from Java

    - by Dan Howard
    Hi All, I'm trying to call a function in JavaScript via Java. This works fine when directly reading a script as a string but I'm using CompiledScripts. When I do this with a compiled script it gives me method not found if I also add bindings. Without bindings it works but of course the function fails because it needs the bindings. Any ideas? CompiledScript script = ... get script.... Bindings bindings = script.getEngine().createBindings(); Logger scriptLogger = LogManager.getLogger("TEST_SCRIPT"); bindings.put("log", scriptLogger); //script.eval(bindings); -- this way fails script.eval(); // -- this way works Invocable invocable = (Invocable) script.getEngine(); invocable.invokeFunction(methodName); TIA

    Read the article

  • Using Java server-side with PHP-generated front-end

    - by Storm
    Hi!  Does anyone have a real-world experience in building such a project? I'd like to move away questions about "is it good idea or not", but focus on possible solutions. I see one simple way - HTTP GET/POST + xml/json - and one more elegant - AJAX/DWR. As for the first one - I understand that it is possible, but needs quite a lot coding. As for second way - is it possible to use Java DWR engine with PHP front-end? Is DWR language-independent for client side (as it uses just JavaScript)?  Would it be a problem, that client page was generated by one web server (for example, apache+php) and served on server-side by another (for example, tomcat)? I suspect, that Tomcat will complain about sessions. Can this problem be fixed with allowing cross-domain AJAX? Thank you in advance. Denis.

    Read the article

  • HPC (mainly on Java)

    - by Insectatorious
    I'm looking for some way of using the number-crunching ability of a GPU (with Java perhaps?) in addition to using the multiple cores that the target machine has. I will be working on implementing (at present) the A* Algorithm but in the future I hope to replace it with a Genetic Algorithm of sorts. I've looked at Project Fortress but as I'm building my GUI in JavaFX, I'd prefer not to stray too far from a JVM. Of course, should no feasible solution be available, I will migrate to the easiest solution to implement.

    Read the article

  • java.io.IOException: Server returned HTTP response code: 403 for URL

    - by Adao
    I want to download the mp3 file from url : "http://upload13.music.qzone.soso.com/30671794.mp3", i always got java.io.IOException: Server returned HTTP response code: 403 for URL. But it's ok when open the url using browser. Below is part of my code: BufferedInputStream bis = null; BufferedOutputStream bos = null; try { URL url = new URL(link); URLConnection urlConn = url.openConnection(); urlConn.addRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)"); String contentType = urlConn.getContentType(); System.out.println("contentType:" + contentType); InputStream is = urlConn.getInputStream(); bis = new BufferedInputStream(is, 4 * 1024); bos = new BufferedOutputStream(new FileOutputStream( fileName.toString()));? Anyone could help me? Thanks in advance!

    Read the article

  • Objective-C : enum like Java (int values and many others for each enum)

    - by Oliver
    In Java, you can make an enum having multiples values. In objective-C, this cannot be done easily. I've read many pages about this but I didn't found anything satisfying that would allow me to use enums by a simple way and to keep the enum declaration and their different values in the same file. I would like to write something like this in a enums.h : // ======================================== typedef enum {eRED, eGREEN, eBLUE} ColorEnum; int colorValues[] = { 0xFF0000, 0x00FF00, 0x0000FF }; NSArray *colorNames = [NSArray arrayWithObjects:@"Red color", @"light green", @"Deep blue", nil]; // ======================================== and be able to use thoses global variables to manage my stuff anywhere like : int color = colorValues[eRED]; But I don't know how to write this. I have compile errors like "ColorValues" is defines many times. Or if I just use "static", I have many "ColorValues" not used in .m file... Could you help me ?

    Read the article

  • problem with jtabbedpane in java..

    - by mani
    hai, is it possible to loading of tabs in jtabedpane dyanamically in java.. that means i have frame that consinting of one tabbedpane.. in that i have 10 tabs and in each tab consting of another tabbedpane and in that each tabbedpane has 4 tabs and each tab consisting buttons and textfields...... when i login into my project the next frame takes more time to visible.... this is happens why because i have more tabbedpanes in my frame so that it takes the lot's of time to visible.. my question is.. is it possible to load tabs content dynamically when i click the tab in tabbedpane..... or is it possible to load tabbedpanes fastly......????????

    Read the article

  • Java library to encode / decode AMF

    - by Ceilingfish
    Hi chaps, I currently have a Java server that talks to a Flash client by passing JSON encoded data over a binary socket connection. Is there a way on either side to encode / decode packets as AMF instead of JSON? It seems to me that there should be some native support in Flash player for doing this? All the implementations I have found of AMF serialization seem to be embedded inside an application framework. Simiarly so, does anyone know if it's possible to decode AMF packets independently of a connection implementation in Flash?

    Read the article

< Previous Page | 267 268 269 270 271 272 273 274 275 276 277 278  | Next Page >